Assuming the majority of miners are KYCed and legislators coordinate requirements, I imagine something like.
Level 1: KYCed miners are required to not process transactions from list of banned addresses. 
Level 2: KYCed miners are also required to not build on top of block with transactions that break level 1 requirement. They can only build on such block if the last n blocks are all breaking this reqirement. This will strongly disinsentivise non-KYC miners from not obeying.
Level 3: change from banned list to allowed list.